Hot-air furnace



(No Model.)

W. MILLER.

HOT AIR FURNACE.

. Patented Feb. 21, .1888

- I vwemtom I I I 35 wtoznmd I MM-lineman NIT'ED STATES PATENT QF ICE.

WILLIAM MILLER, OF GRAND RAPIDS, 'MICHIGAN., A

HOT-AIR FURNACE.

SPECIFICATION forming part of Letters Patent Np. 378,10], dated February 21, 1888.

Application filed July 28, 1886. Serial No. 209,334. (No model.)

' To all whom it mag concern.-

Be it known that I, WILLIAM MILLER, a citizen of the United States, residing at Grand Rapids, in the county of Kent and State of Michigan, have invented a new and useful Improvement in Hot-Air Furnaces, of which the following is a specification.

My invention relates to improvements in hot-air furnaces in which the furnace and radiator are inclosed in a casing, to which is attached suitable pipes to convey the heated air to the desired points for use, and having a suitable inlet near the bottom to admit cold air.

The objects of my improvements are topicvide a furnace and radiator of cheaper construction and easily kept in order, to provide 1 for a more effective draft in aid of combustion, and to provide for the unequal expansion of the various parts of the furnace and radiator.

I attain these objects by the mechanism illustrated in the accompanying drawings, in which Figure 1 is a vertical section on the line 00 w of Fig. 2. Fig. 2 is a horizontal'section on the line yy of Fig. 1; Fig. 3, an enlarged portion showing the manner of providingfor the expansion of the sheet-iron sides.

Like letters refer to like parts in all the figures.

A is an upright rectangular furnace, the ends a: a consisting of cast-iron plates and the sides I) b of sheet-iron plates. At the top said sides curve to one side and approach each other to within a short distance, as shown, the side I) formingthe top of the furnace, into which the direct-draft pipe B is inserted. These said sides and ends are prolonged in the form of a convenient number of the described convoluo tions may be added, and they may terminate either at the top or bottom of the casing.

A furnace and radiator thus constructed consists of a single continuous chamber of considerable length, having one end enlarged and containing the fire, and from thence being a continuous serpentine flue having a pipeattached to the other end, is in compact form, and presents alarge radiatingsurfacein small compass, and very cheaply constructed. It also offers much less resistance to the passage of the products of combustion than any 'form of furnace having a radiator attached having alternately narrow and wide passages for the said products of combustion to pass through. 6 5

0 is a grate upon which the fuel is burned.

d is a door to admit said fuel, havinga suitable casing extending through the""'riia'sonry and attached to the end plate.

d is a similar door opening into an ash-pit under said grate.

f are fire-bricks to protect the iron of the furnace.

g g are openings for removing any accumulations in the radiator. Said openings have pipes h h attached, which extend through the masonry, and are closed by caps t i.

The edges of the sides 11 b abut against the inner surface of the ends a a, upon which are flanges k, which comein contact with the inner surfaces of said sides and keep them inposition.

Passing through the ends a a and outside of said sides I) b are tie-rods e, which hold the structure together and keep the sides b b from springing away from the flanges'lc It. At all points where the'flanges It would, if continuous, abut against the convex surfaces of the sides I) said flanges are transposed to the concave side of the sides b, as shown at k. I thus avoid any compression of said sheet-metal sides when they expand unequally with the ends a. v v

I am aware that a furnace having alternating vertical flues inclosed with masonry and 5 provided with pipes and inlet-passages for air is not new. I do not claim thesebroadly. What I claim and wish to secure is- In a hot-air furnace, a radiator consisting I at the concave side of said side plates, where of a continuous flue having a passage of unithe return-bends occur, substantially as deform area and rectangular cross-section, also scribed.

having semicircular return-bends, the sides of WILLIAM MILLER. 5 said flue consisting of two end and two side Witnessess:

plates, said endplates having flanges engaging I L. V. MOULTON,

with said side plates, said flanges beinglocated ETTA TOWN. 

